'appressorium-related' is a compound of 'appressorium' + 'related'. 'appressorium' originates from New Latin 'appressorium', ultimately derived from Latin components related to 'appressus' (past participle of 'apprimere'), where 'ad-/ap-' meant 'to, toward' and 'premere' meant 'to press.' 'related' comes from Latin 'relatus', the past participle of 'referre'.

'appressorium' was coined in scientific/Neo-Latin usage by mycologists to name a pressing/attachment structure and later adopted in modern English mycological terminology; 'related' passed into English via Old French and Middle English from Latin 'relatus'. The compound 'appressorium-related' is a modern technical adjective formed by combining the technical noun with the common adjective 'related'.

Originally the Latin elements behind 'appressorium' referred generally to pressing or applying pressure; in biological terminology the meaning narrowed to a specific fungal attachment/penetration structure. 'Related' originally signified 'brought back' (in the sense of 'reported' or 'carried back') in Latin but evolved in English to mean 'connected' or 'having relation to'.